Need help with fuel bowl vent on Holley 2300..
 

Discovered a major fuel leak through the vent hole on the top of my rear secondary carburetor. It's a 2300, actually a list number 2437 that's the rear carb of the tripower setup on my 1962 Galaxie. It's just a 1/4" hole with a loose fitting metal cap, no seal. Here's the hole:


https://www.fordbarn.com/forum/pictu...ictureid=47322


Here's the cap:


https://www.fordbarn.com/forum/pictu...ictureid=47323


There was no vent valve in the carb when I disassembled it. A vent valve came in the carburetor kit but the diagram seems to show it resting on top of the cap outside the bowl which makes no sense. The diagram also shows five pieces of hardware associated with a vent rod as well as a vent valve retainer. None of these pieces were present when I disassembled the carb.


One thing that's not helping is that I think the float's set too high. I only had a chance to set the dry float and shut down the car to fix the leak and didn't keep it running long enough reset the float.


There are no vent holes in the other secondary or in the primary. Obviously I have a mismatched setup. What do I do?


1. Plug the hole and move on
2. Install the vent valve with no vent rod or associated hardware. I don't see how to do this. The diagram I have makes no sense to me. I don't see how you can have a vent valve with a vent cap.
3. I'm not going to get a vent rod andl associated hardware because i don't think that's correct for the car.
4. Find another fuel bowl without a vent hole



https://www.fordbarn.com/forum/pictu...ictureid=47327




https://www.fordbarn.com/forum/pictu...ictureid=47326


I'm really stumped.

Re: Need help with fuel bowl vent on Holley 2300..
 

If fuel is coming out of that vent hole, then the carb is flooding over, either from dirt in the fuel valve or just defective. Could also be excessive fuel pressure.
You can just put the cup shaped metal cap back over it. Don't worry about the other two carbs, since they still have bowl vents instead of a hole on top of the bowl.

Sal

Re: Need help with fuel bowl vent on Holley 2300..
 

Can you post the ID NOS off the air horns (all three)?

Re: Need help with fuel bowl vent on Holley 2300..
 

The list numbers, parts numbers and date codes are consistent with a 1962 G-code Galaxie built in August 1962.


Front: date - 264
part #C1AE9510-AU
list #2437


Middle: date - 222
part #C1AE9510-AV
list #2436


rear: date - 264
part #C1AE9510-AU
list #2437



Front and rear carb numbers are identical even thought the fuel bowls aren't. Probably the rear fuel bowl with the vent hole is from something else. Since the fuel bowls all vent through the metering blocks to the vent tube, I'm thinking the extra vent hole in the real fuel bowl is unnecessary. I'm leaning towards simply plugging it rather then just reinstalling the vet cap that allows fuel to slosh out.


Front carb:


https://www.fordbarn.com/forum/pictu...ictureid=47333


Middle Carb:


https://www.fordbarn.com/forum/pictu...ictureid=47334


Rear carb:


https://www.fordbarn.com/forum/pictu...ictureid=47333

Re: Need help with fuel bowl vent on Holley 2300..
 

My fault, I should have asked for an overhead showing all three bowls and their vent style.

The main bodies are correct.

Might have needed @ some point a bowl and he took one off another H2300.

The vents are there for a reason and cannot (should not) be blocked off.

Re: Need help with fuel bowl vent on Holley 2300..
 

The vent cap in the kit is the correct vent for these carbs -

You say the rear carb has the wrong fuel bowl (not off the correct H2300)?

The primary (1) and secondary carbs (2) take different fuel bowls as the float levels on the outboard carbs are in a different position. That may be your flooding issue as the fuel level is set too high.

Where did you source the kit? Is it ethanol rated?

Re: Need help with fuel bowl vent on Holley 2300..
 

All nine of my carbs have the vent caps. (3 different set ups, Bird and Galaxie)
I have to think the ones without the caps have had the bowls replaced at some time in their life. They should still function ok without the cap.
I have gone out of my way to take a replacement bowl and machine it for that little cap to make them look correct.

Re: Need help with fuel bowl vent on Holley 2300..
 

The bowls have to be vented.

I think what is throwing him is at some point, someone used a bowl off another H2300 application without realizing there are difference(s) and not sourcing the correct bowl.

C1AE-9510-AV - LIST 2436 (PRI) - FUEL BOWL - C1AZ 9A507-B (1)
C1AE-9510-AU - LIST 2437 (SEC) - FUEL BOWL - C1AZ 9A507-C (2)

If NOS bowl(s)cannot be found, one may have to buy a complete core.

Later HOLLEY used a different vent setup (see below) -

Re: Need help with fuel bowl vent on Holley 2300..
 

I jumped over this ... :o

That ILL is showing the later vent style . That is what has you.

The 1960-64 FORD CAR MPC ILL did the same thing.

Re: Need help with fuel bowl vent on Holley 2300..
 

I agree the bowls need to be vented only to make the carbs concourse correct, if that's your objective, but there are plenty of Holley's made without a vent on the bowls. All have a main vent for the bowls located on the choke tower wall.

Sal

Re: Need help with fuel bowl vent on Holley 2300..
 

Yes, that sounds right. Thanks for the reply. The rear bowl with the vent hole appears correct and the float level is too high. Hate adjusting float levels with gas everywhere. Did not know that cap was a thing. Hate it. Given the vent tube up through the choke tower wall I may just plug it. I love original but there are limits. No, the kit did not include vent caps but it did include vent valves. Thanks for clearing up my questions about the diagrams. It was a Holley rebuild kit I got from Summit Racing.

Re: Need help with fuel bowl vent on Holley 2300..
 

These are external bowl vents being disussed. The vent(s) you are describing are main vents.

The external vents allow fuel vapor(s) pressure to be expelled into the atmosphere without being drawn into the carb body upsetting fuel mixture.

That early carb design progressed through the years to allow for internal venting (pollution control).

Re: Need help with fuel bowl vent on Holley 2300..
 

Those vents provide fuel bowl vapor escape. The main vents do not do that on the fuel bowl design you have.

Do you feel the carb bowl you have being discussed is the correct one? Does the sight plug height match the front carb sight plug (center and ends are different heights)?

Where did you find the vent cap? If HOLLEY, do you have a PN?

If you modify it, you have lost value.

Re: Need help with fuel bowl vent on Holley 2300..
 

I like original but I may add rather than destroy value with a few targeted improvements on my genuine G-code Galaxie. Here's a G-code auction with a few improvements.
https://bringatrailer.com/listing/19...alaxie-500-39/


For my own pleasure I'm thinking about a 3-deuce fuel injection system, a TKX 5-speed, and disc brakes.


I've now have correct 15x5.5 KH cat-eye wheels. They look good!

Re: Need help with fuel bowl vent on Holley 2300..
 

No, I have not modified anything. Thanks for the reply. Given everything, sounds like the rear carb bowl with vent and vent cap is correct. I also believe the carb bowl is the correct one. Only because of this discussion. The vent cap came with the carb. I'll check the sight plug heights tomorrow.

Re: Need help with fuel bowl vent on Holley 2300..
 

With those 'improvements', it is not going to be a GENUINE G-CODE.

Well, it was an interesting exercise regardless.

GOOD LUCK with it.

Re: Need help with fuel bowl vent on Holley 2300..
 

Here we go, I found the INSTRUCTION SHEET on the HOLLEY website -

The ILL shows both the early vent cap (31) and the following design vent cap (33).

31 does not show on the kit LIST of INGREDIENTS but you say it was included in the kit? Sounds like FORD as one kit could renew several different applications.

At least that was solved ... ;)

Re: Need help with fuel bowl vent on Holley 2300..
 

"Those vents provide fuel bowl vapor escape. The main vents do not do that on the fuel bowl design you have.

Do you feel the carb bowl you have being discussed is the correct one? Does the sight plug height match the front carb sight plug (center and ends are different heights)?"


The vent caps on the bowls and the main vents on the choke tower both vent the bowl, and the site plugs on all of the bowls are at the same height.

Sal

Re: Need help with fuel bowl vent on Holley 2300..
 

Again, this early style fuel bowl(s) has exterior bowl vents (outside of the ACL ring - filtered air) to exhaust any vapors formed in the bowls (from engine heat) (pre-EVAP compliant) from venting back into the main vent. If those fumes did vent in that manner it would upset the fuel mixture.

There is a primary bowl and two secondary bowl(s). The fuel level adjustment(s) are different. That is why two different bowls. The fuel sight plugs are at differing heights for correct wet adjustment.

I gave the bowl PN's in a post above.

The bowl vent design was changed around 1965 (pollution control) I believe to vent (within the ACL) as you are describing.

EDIT -

The HOLLEY FORD DEDICATED CARB (2V and/or 4V) (not all 2V) used exterior fuel bowl vents until the HOLLEY was dropped after the 1971 MODEL RUN (not considering the later H4180 design emissions complaint).


This THREAD has been altered also ...

No use for further posting and trying to share/trade information.

Re: Need help with fuel bowl vent on Holley 2300..
 

Now we're getting somewhere.


According to ChatGPT
"during heat soak, a poorly vented bowl can lead to:

• Fuel expansion and percolation,
• Boiling fuel pushing out into venturis,
• Engine hard starting, flooding, or even backfire."

I'm certain boiling fuel is pushing out into venturis and I do have hard engine starting and likely flooding.


Venting contrary to design may be the cause of my heat soak issues. There are also internal vents in the metering blocks that go to the main vent tube. Is that correct for a 1962 tri-power setup?


It's pretty hard to find carburetor bowls with vent caps. Obviously holes are easy to drill but machining the bowl to secure the vent cap is harder.


I did find one with a vent cap from a 4-barrel and may take a chance on it.